FOEE8T MARBLE : SWINDON. 359 
Again in a quarry south of Newnton House, two miles S.E. 
of Tetbury, the following section was to be seen : 
FT. IN. 
"Grey clay - - - - 1 6 
Calcareous sandstone with carbona- 
ceous specks, and oolite : the former 
Forest Marble - 
passing into sand, with impersistent 
hard beds which are flaggy and 
ripple-marked, and sometimes con- 
cretionary : the oolite at various 
horizons - - 
The general section in this part of Wiltshire may be stated to 
be as follows* : 
FEET. 
["Clays with thin hands of gritty lime- 
stone - - - - - 10 to 15 
Sands and calcareous sandstone - 5 to 10 
Forest Marble -^ Oolitic and sandy limestones, passing 
I down into more shelly limestones 
and clays - - - - 20 to 30 
^Bradford Clay - - - - 2 to 6 
Total thickness about 60 
Swindon and the London area. 
Towards Swindon the Forest Marble appears to be considerably 
reduced in thickness, as shown by the records of well-borings at 
Chippenham (see p. 507), and of a well-sinking made by the 
Great Western Railway Company at Swindon. 
The Great Oolite was not actually proved at Swindon, but 
the fossils from the Forest Marble indicated the basement-portion 
of that formation, and we have evidence of only 33 feet of the 
strata. (See p. 515.) In this sinking the beds penetrated at 
depths of from 703 feet to 736 feet, proved to be Forest Marble. 
The fossils were chiefly obtained from the lowest part, about 730 
feet, in the thin clay-partings of harder shelly rock : and the 
following species have been identified : 
Cerithium. 
Area. 
Avicula. 
Lima duplicata. 
Modiola imbricata ? 
Ostrea gregaria. 
Hngulata ? 
Sowerbyi. 
Pecten lens. 
vagans. 
Ehynchonella concinna. 
Terebratula coarctata. 
Waldheimia digona. 
obovata. 
Diastopora diluviana. 1 
Entalophora straminea. 
Terebellaria ramosissima. 
Acrosalenia (spines and platesj. 
Cidaris (spine). 
Pentacrinus scalaris. 
Serpula tetragona. 
tricarinata. 
(Lignite). 
I descended the shaft, in company with Mr. E. T. Newton, but it 
was not possible to note any details of the strata in situ. The 
* See also Lonsdale, Proc. Geol. Soc., vol. i. p. 415 ; and Hull, Geol. parts of 
Wiltshire, &c., p. 16. 
